The kinetics of O transport in La0.5Sr0.5CoO3 were investigated by using the conductivity relaxation technique at 600 to 700C, under O partial pressures ranging from 0.01 to 1atm. The effects of O partial pressure upon the chemical diffusivity of O and the surface exchange coefficient were investigated by systematically changing the initial and final O partial pressures. The results showed that for O partial pressure switches, with initial/final pressure ratios greater than 20, a linear model for the exchange kinetics was no longer valid.

The Effect of the Magnitude of the Oxygen Partial Pressure Change in Electrical Conductivity Relaxation Measurements - Oxygen Transport Kinetics in La0.5Sr0.5CoO3. S.Wang, A.Verma, Y.L.Yang, A.J.Jacobson, B.Abeles: Solid State Ionics, 2001, 140[1-2], 125-33